Soapmaking



Patented Apr. 13, 1943 SOAPMAKING Robert Franklin Heald and Albert LyleSchulerud,

Nutley, N. J., assignors to Colgate-Palmolive- Peet Company, JerseyCity, N. J a corporation of Delaware No Drawing.

Application June 5,1941,

Serial No. 396,718

11 Claims.

The present invention relates to a process for making a detergent in theform of bars and cakes bars and cakes of soap are desired, there arelimitations upon the amounts of the builders and fillers which can beadded and still produce soap in this form. Thus, it has always beenassumed by the art that theincorporation of large amounts of thesematerials in soap batches and soap compositions would make it impossibleto obtain the soap in the form of bars and cakes. For example, the priorart believed that the practical upper limit upon the proportion of boraxwhich could be embodied in a bar or cake of soap was of the order ofabout 15 to about It has now been discovered that, by the novel processof the present invention, a far larger proportion of certain buildersand fillers can be incorporated in bar and cake soap.

It is an object of the present invention to provide a method forproducing a soap in the form of bars and cakes having a relatively largeproportion of an inexpensive builder,

It is another object of this invention to provide a process ofmanufacturing soap in bar or cake form whereby the product isinexpensive, has good water-softening properties, and is not harmful tothe human skin.

It is also an object of the invention to provide a process for making ablander and more neutral soap than the oridnary soaps of commerce.

A further object of the. present invention is to provide a process forincorporating large amounts of borax in bars and cakes of soap, wherebyan inexpensive hand soap well adapted for grinding can be produced.

The invention also provides a. process for producing soap in bar or cakeform suitable for toilet and/or household uses and containing a largeproportion of borax.

Other objects and advantages of this invention will be apparent from thefollowing description.

According to the present invention, bars of soap containing largeamounts of an inexpensive builder can be produced by incorporating asuitable material in soap compositions during their manufacture. Boraxhas been found to be particularly suitable for this purpose, as itcombines the properties of a cheap ingredient, a good water-softener,and an agent without appreciable harmful effect upon the skin. Unlikemost builders, which raise the pH of soap above the usual 10.0 to 10.5of unfilled soaps, borax reduces the pH of the soap and, in thequantities contemplated in the present invention, a product having a pHof only about 9.0 to about 9.5 can be produced. Thus, due to the bufferaction of borax, its presence in large quantities in a toilet soapactually makes the soap more neutral, and hence more bland, which is adesirable characteristic.

A surprising feature of the invention is the fact that about 25 to aboutof borax (on an anhydrous soap plus borax basis) can be employed inmanufacturing soap, and the soap can still be formed into cakes andbars. When using more than about 60% of borax upon this basis, eventhough a bar may be formed, such soap would be too hard and brittle forconvenient use. It is preferred to use proportions of about 45 to about55 parts of borax to about 45 to about 55 parts of anhydrous soap in thesoap bars and cakes of the present invention, particularly where theappearance of the soap is not important. Thus, cakes of toilet soaphaving about 45 to about 55% of borax upon the aforesaid basis are welladapted for use in dispensers where the soap is concealed from view andgrinding means are provided for enabling the consumer to grind a smallamount of the soap for immediate use,

In manufacturing the novel soap cake of the present invention, it ispreferred to make up a kettle soap composition in the usual manner,flake, and dry. The flaked soap is then mixed with the desiredproportion of borax, and a small amount of water is preferably added.The mixture is then milled and plodded, and it is preferred that themixture be plodded in accordance with the process disclosed by Schwantesin his United States Patent No. 2,146,770. When the moisture content iscarefully controlled, a small amount of heat is produced, and, underproper conditions of temperature and moisture, the mixture is easilyworked. It has been found that a satisfactory temperature is one betweenthe point of plasticity of the mass, say about F. or slightly lower, andthe point where the soap begins to blister, i. e., about F., or evensomewhat higher when using the process of the Schwantes patent. Uponcooling, the soap hardens, and at least part of the borax apparentlycrystallizes. A relatively hard and brittle product, admirably adaptedfor grinding, is formed.

a moisture content of about 12.0%.

Borax, NR-2B407.10I'I20, contains about 47.24% of water ofcrystallization and is sometimes damp with excess water; such excess istaken into account before adding further quantities of water to thecomposition, At times, borax is received so badly lumped that it isdesirable to grind the borax before attempting to use it.

It permitted to stand in a dry atmosphere, borax tends to lose some ofits water 01' crystallization, so that it is always desirable to run amoisture analysis upon the borax to determine the proportion of sodiumtetraborate present therein. It will be understood from the foregoingthat, where part of the water of crystallization has been lost, lessborax and more water are added to the soap.

In order that those skilled in the art may have a better understandingor this invention, the following illustrative examples are given.

Example I Per cent Anhydrous soap About 41.8 Sodium tetraborate About25.5 Water About 32.7

which is about 53.7% borax (the decahydrate) on a borax-anhydrous soapbasis. Small amounts of various materials for giving the product greateropacity, such as titanium dioxide, zinc oxide and other pigments, can beincorporated in the soap, and perfumes and preservatives can also beadded as desired.

Where the borax has lost some of its water of crystallization, so thatit gives an analysis of about 54.5% of sodium tetraborate, theproportions used in order to obtain a soap with approximately the sameanalysis are 220 pounds of white soap chips to about 212.75 pounds ofborax (54.5%) and about 22.25 pounds of water. If still more water ofcrystallization is lost, so that the analysis of the borax runs as highas about 56% sodium tetraborate, only about 207 pounds of this borax andabout 28 pounds of water are added to the 220 pounds of white soap chipto produce approximately the same soap.

It has been found that the greatest proportion of water must be presentas water of crystallization in the borax, if a satisfactory soap is tobe produced. Thus, according to the present invention, it is undesirableto employ borax which analyzes higher than about 56% sodium tetraborate.The addition of sumcient water to compensate for the loss of water ofcrystallization makes the soap very difllcult to work.

Example II A kettle soap is made having a base of about 50% palm oil,about olive oil and about 25% coconut oil, and the same is flaked anddried to About 220 pounds of the chips thus prepared are then mixed withabout 12 pounds of water and with about 180 pounds of borax analyzingabout 52.76% sodium tetraborate. This mixture is milled and plodded, theplodding operation being carried out according to the process ofvSchwantes United States Patent No. 2,146,770. Upon mixing, thetemperature of the mass goes to about F., and the friction of themilling operation raises it to about F. This is ordinarily warm enoughfor easy working, so that addition of heat from an external source isnormally unnecessary. A hard, green soap adaptable for pressing isproduced. The soap analyzes as follows:

Per cent Anhydrous soap About 47.0 Sodium tetraborate About 23.0 WaterAbout 30.0

The borax percentage on the borax-anhydrous soap basis is thus about48.1%. Just as in Example I,- the proportion of water added is largelydependent upon the moisture analysis of the borax. Similarly also,pigments, perfumes and preservatives can be added as desired.

Other materials may be substituted for part of the borax in our improvedsoap bars. Thus, where it is intended that the soap be adaptable for usewith hard water, materials such as phosphates, e. g., tetrasodiumpyrophosphate, sodium hexametaphosphate, and the like, or other builderscan replace part of the borax in the composition according to thisinvention. Water is added to the composition to make up for thedifierence in water content between the borax and the phosphate added.Other materials commonly incorporated in cakes and bars of soap, such asabrasives, colors, perfumes, deodorants, germicides, superfattingagents, etc., can similarly be employed in the soaps of the presentinvention.

Example III About 220 pounds of white soap chips are mixed and ploddedwith about 132 pounds of borax (analyzing about 52.76% sodiumtetraborate),"about 44 pounds of sodium pyrophos- -phate and about 59pounds of water. The soap obtained is comparable with that obtained inExample I but has increased water-softening characteristics.

In another modification of the present process, borax can beincorporated in the soap composition in a crutching operation. Accordingto this modification, a kettle soap is cmtched with borax in suchproportion as to give the desired composition in the final driedproduct. After crutching, the soap is dried to a chip, milled andplodded. In general, this modification, as compared with that describedsupra, has the disadvantages of increased equipment costs and ofinsuilicient heat to permit easy working, and it is ordinarily desirableto add heat during the crutching in order to maintain fluidity of themass. Such heat can be added by any. convenient means, such as passingsteam through a jacket surrounding the crutcher, and the mix may beheated to a temperature of about F. to about 180 F.

Example IV About 1,020 pounds of white kettle soap, made from a base ofabout 20% coconut oil and about 80% tallow and having a moisture contentof about 30%, are crutched with about 580 pounds of borax (analyzingabout 52.76% sodium tetraborate) in a crutcher heated to about F.

The soap is then dried to remove part of the moisture and to form chipsand is milled and plodded. The drying and subsequent operations arecarefully controlled to leave the desired amount of moisture in thecomposition. A soap having the following analysis is produced:

Per cent Anhydrous soap About 49.4 Sodium tetraborate About 21.2 WaterAbout 29.4

This gives about 44.8% borax on the borax-anhydrous soap basis.

If desired, the soap from the crutcher can be framed and cut, butdrying, milling and plodding is preferred. The frame soap gives a softerbar not as well suited for grinding in a dispenser. In this connection,it may be noted that some lowtitre soap cannot be milled, but borax canbe incorporated by the present process with any soap which can form anunfilled chip.

Although the present invention has been described with respect toparticular illustrative examples and compositions, it will be understoodby those skilled in the art that equivalent substances and proportionscan be employed and that variations and modifications may be introducedwithout departing from the principles of the present invention. Suchvariations and modifications are believed to be within the scope of thepresent specification and within the purview of the appended claims.

We claim:

1. The process of making bars and cakes of soap' which comprises mixingsoap with borax in such proportion that borax is present in an amount atleast about 25% of total borax and anhydrous soap in the mixture,milling the mixture, and forming bars and cakes therefrom.

2. The process of making bars and cakes of soap which comprise mixingsoap with borax in such proportion that borax is present in an amountabout 25 to about 60% of total borax and anhydrous soap in the mixture,thereafter milling and plodding the mixture, and forming bars and cakestherefrom.

3. The process of making bars and cakes of soap which comprises mixingsoap with borax in such proportion that borax is present in an amountabout 25 to about 60% of total borax and anhydrous soap in the mixture,milling said mixture, plodding at a temperature between the point ofplasticity of the mixture and the blistering point, and forming bars andcakes therefrom. 4. The process of making bars and cakes of soap whichcomprises mixing soap with borax in such proportion that borax ispresent in an amount about 25 to about 60% of total borax and anhydroussoap in the mixture, milling said mixture, plodding at a temperature ofabout 120 to about 140 F., and forming bars and cakes therefrom.

5. Ijhe process of making bars and cakes of soap which comprises mixingunfilled. soap with borax in such proportion that borax is present in anamount about to about of total borax and anhydrous soap in the mixture,milling the mixture, and forming bars and cakes therefrom.

6. The process of making bars and cakes of soap which comprises mixing achipped soap with about 25 to about of borax on a boraxanhydrous soapbasis, said borax having a sodium tetraborate content of not more thanabout 56%, and with suflicient water to make the mixture easilyworkable, thereafter milling and plodding said mixture, and forming barsand cakes therefrom 7. The process of making bars and cakes of soapwhich comprises mixing a chipped soap with about 25 to about 60% ofborax on a borax-anhydrous soap basis, said borax having a sodiumtetraborate content of not more than about 56%, and with sufiicientwater to make the mixture easily workable, milling said mixture,plodding at a temperature of about to about F., and forming bars andcakes therefrom.

8. The process of making bars and cakes of soap which comprises flakingand drying kettle soap to a moisture content of about 12 to about 13.5%,mixing about 45 to about 55 parts of said fiaked soap (on an anhydroussoap basis) with about 45 to about 55 parts of borax having a sodiumtetraborate content of not more than about 56% and with sufficient waterto make the mixture easily workable, thereafter milling and ploddingsaid mixture, and forming bars and cakes therefrom.

9. The process of making bars and cakes of soap which comprises flakingand drying kettle soap to a moisture content of about 12 to about 13.5%,mixing about 45 to about 55 parts of said flaked soap (on an anhydroussoap basis) with about 45 to about 55 parts of borax having a sodiumtetraborate contentof not more than about 56% and with suflicient waterto make the mixture easily workable, milling, plodding said mixture at atemperature of. about 120 to about 140 F. to form a borax soap, dividingsaid plodded soap into bars and cakes, and cooling said soap.

10. The process of making bars and cakes of soap which comprisescrutching kettle soap with about 25 to about 60% of borax on aborax-anhydrous soap basis, drying the crutched composition, formingchips therefrom, thereafter milling, plodding, and forming bars andcakes therefrom.

11. The process of making bars and cakes of soap which comprisescrutching a kettle soap having a moisture content of the order of about30% with an amount of borax suflicient to give a proportion of about 45to about 55% of borax in the mixture on a borax-anhydrous soap basis.maintaining thetemperature of the mixture during crutching at about toabout F.. removing part of the water from the crutched mixture to leavea predetermined amount of moisture therein, thereafter milling andplodding the mixture, and forming bars and cakes therefrom.

ROBERT FRANKLIN HEALD. ALBERT LYLE SCHULERUD.

